The first two wave types, P and S, are called body waves because they travel or propagate through the body of Earth. The latter two are called surface waves they the travel along Earth's surface and their amplitude decreases with depth into Earth.
Toysmith Spring Ring Game. Here is a super fun game the kids might like. Nordstrom has this Toysmith Spring Ring Game for $14.98! That is down from the normal price of $24.99, for a 40% savings.
It cost $13, $15 if you count the gum I purchased along with it because I suddenly turned into my 14-year old self (the girl who was embarrassed to buy tampons) and didn't want to be seen purchasing just a vibrating ring.